Monoclonal antibodies are increasingly important therapeutic, diagnostic, and research agents in the field of oncology. Characterizing their binding sites on target antigens can elucidate cancer-specific topological arrangements, and can aid in the development and selection of optimized MAbs. However, there are currently no commercial tools available that enable automated, rapid functional analysis of MAb epitopes in membrane proteins and other structurally-complex cancer biomarkers. Integral Molecular is developing a novel technology that addresses the bottleneck in conventional mutational analyses: the expression and analysis of large libraries of point-mutated proteins. In this proposal, we will use this technology to map the epitopes of MAbs directed against structurally-complex cancer biomarkers that are resistant to direct structural analysis.